Programmable read-only memory (PROM), field programmable read-only memory (FPROM), and one-time programmable non-volatile memory (OTP NVM) are types of digital read-only memory (ROM) where the setting of each bit is set by a fuse or an antifuse. In fuse-based technology, the fuse starts with a low resistance and is designed to permanently break an electrically conductive path when the current applied to the path exceeds a specified limit. Similarly, in antifuse technology, each antifuse starts with a high resistance and is designed to permanently create an electrically conductive path when voltage across the antifuse exceeds a specified limit. Each fuse or antifuse represents a digital bit, and burning specific fuses or antifuses creates digital data on the ROM. PROMs are manufactured blank and may be programmed at wafer, final test, or in system.